页岩油储层具有低孔、低渗的特性，需要采用大规模压裂改造才能够获得商业产能。页岩脆性以及储层可压裂性的科学评价对压裂改造层位优选以及压后产能评估的具有重要意义。现有脆性评价方法依靠岩石力学实验或者特殊测井数据，难以在井区大规模运用，同时页岩脆性对储层整体可压裂性的控制机理尚不明确。项目对页岩岩屑开展纳米压痕实验，根据能量贯穿于材料断裂全过程且不受尺度影响的观点，从能量演化角度建立页岩微观脆性指数。基于多尺度均匀化理论建立页岩宏细观力学参数预测模型，结合离散元数值方法，研究页岩微观脆性对宏观断裂的影响，并以裂缝尖端断裂过程区为切入点，建立考虑微观脆性的页岩水力裂缝起裂模型以及裂缝穿层/转向判定模型，综合起裂特征和裂缝扩展模式建立全新的可压裂性定量评价模型，揭示页岩微观脆性对储层宏观可压裂性的控制机理。本研究对实现随钻快速连续评价页岩油储层有利层段以及优化压裂设计方案具有重要的指导意义。

Shale oil reservoir has the characteristics of low porosity and low permeability, which requires large-scale hydraulic fracturing to obtain commercial production. The scientific evaluation of shale brittleness and reservoir fracability is of considerable significance to optimize the hydraulic fracturing position and evaluate productivity. The existing brittleness evaluation methods rely on lab rock mechanics experiments or special logging data, which are difficult to be widely used in in the field. Also, the control mechanism of the rock matrix’s brittleness on the fracability of the shale reservoir is not clear. In this project, nano-indentation experiments will be carried out on shale cuttings and a new micro brittleness index of shale will be established from the perspective of energy evolution based on the viewpoint that energy penetrates the whole failure process of rock material and is not affected by scale. According to the theory of multi-scale homogenization, the prediction model of macro and micro mechanical parameters of shale will be established, and the effect of micro brittleness on macro fracture of shale will be studied by combining theoretical model with discrete element numerical method. On this basis, the initiation model and crossing/deflection prediction model of hydraulic fracture in the shale reservoir will be deduced by considering micro brittleness of shale and introducing the fracture process zone (FPZ) at the fracture tip. Finally, a new quantitative evaluation model of shale reservoir’s fracability will be established by synthetical consideration of fracture initiation and fracture propagation mode, which can reveal the control mechanism of micro brittleness of rock matrix to the macro fracability of shale reservoir. This study contains crucial guiding significance for realizing the rapid and continuous evaluation of favorable reservoir and optimizing the hydraulic fracturing design scheme.